Gauges and other indicating devices have long been used in monitoring fluid systems, such as HVAC systems, clean room systems, paint booths, dust collectors, etc. A common instrument used for determining a fluid pressure parameter, such as differential fluid pressure, includes a movable indicating needle having a deflection state that corresponds with a difference in pressure across a membrane or the like. A typical application for such a device might be gauging a differential pressure between two separate areas. While such mechanical gauges are relatively stable and reliable, they do not enable direct control, data logging, and a host of other capabilities desirable in the context of modern fluid system applications. For instance, it may be desirable for a technician to obtain a record of maximum or minimum absolute pressures in one part of a fluid system, maximum or minimum differential pressures between separate parts of a fluid system, or even ranges between maxima and minima over a period of time. Other than visual inspection and recording, most mechanical systems do not provide these and other capabilities. The measurement precision available with mechanical instruments may also be insufficient for certain applications.
In an attempt to provide more sophisticated indication and control in various fluid system applications, engineers have developed a host of electronic systems to replace or supplement traditional mechanical gauges. Systems are known wherein membrane deflection, for example of a piezoresistive element, is used to generate an electrical signal representative of an absolute or differential pressure. Such systems are often equipped with a processor for interpreting the signals and displaying them on a display and/or logging pressure sensor data in electronic storage.
One differential pressure controller of this general class is manufactured by Dwyer Instruments of Michigan City, Ind., and known commercially as the Digihelic. This device has separate high pressure and low pressure ports to enable a sensing device to determine a differential pressure therebetween. There is further provided a menu structure whereby various of the functions of the device may be set to specifications, such as selection of units of measure in which monitored pressure will be displayed. While the ability to change certain of the parameters may be restricted, the Digihelic provides little, if any, flexibility in structuring the menus themselves.
A further shortcoming of the aforementioned instrument, as well as others of its general class, relates to the individualized programming and/or set-up required for multiple units. In other words, no facile means is known from the field of pressure instrumentation whereby multiple units can be readily provided with identical programming to suit identical or similar applications, or where logged data can readily be downloaded from multiple units, without additional wired connections.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.